TWI534229B - New dispersion adhesives, a process for preparing them and use thereof - Google Patents

Description

Novel dispersible binder, preparation method thereof and use thereof

This invention relates to novel aqueous dispersion binders, to processes for their preparation and to their use in the furniture and automotive industries.

TDI isocyanate dimers have been used to date in dispersion adhesives mainly used in the furniture industry, for example like Desmodur TT or Addolink TT, see EP 0 922 720A. Such an application is described in detail, for example, in "Polyurethane-Lacke, Kleb-and Dichtstoffe" (Hanover: Vincentz Network, (2007), pages 262-273) by Ulrich Meier-Westhues (Technologie des Beschichtens). These materials have the disadvantage that their preparation is expensive and, given the possibility of releasing toxic TDI, their application possibilities in the automotive industry (inside the car) are limited.

It is therefore an object of the present invention to provide an inexpensive alternative to aqueous dispersion binders, especially in the automotive industry.

Surprisingly, it has now been found that aqueous dispersion binders comprising certain carbodiimide and polyurethane dispersions do not have the disadvantages of the prior art and are particularly suitable as dispersion adhesives for use in the furniture and automotive industries. .

The present invention therefore provides a plurality of aqueous dispersion binders comprising at least one polyurethane dispersion and at least one carbodiimide having the following formula (I)

R'-(-N=C=NR-) _m -R" (I),

Wherein m corresponds to an integer from 1 to 500, R = an aryl group, preferably a C ₆ -C ₁₅ -exylaryl group and/or a C ₇ -C ₁₁ arylalkylene group, R'=R-NCO, R-NHCONHR ¹ , R-NHCONR ¹ R ² or R-NHCOOR ³ , and R"=-NCO, -NHCONHR ¹ , -NHCONR ¹ R ² or -NHCOOR ³ , wherein, in R', R ¹ and R ² are independent of each other, It is the same or different and represents a C ₁ -C ₆ alkyl group, a C ₆ -C ₁₀ cycloalkyl group or a C ₇ -C ₁₈ aralkyl group, and R ³ has ^one of the definitions of R ¹ .

It is likewise possible to use mixtures of carbodiimides of formula (I), including the corresponding oligomers and/or polymers.

Preference is given to using monomeric carbodiimides of the formula (I) based on aromatic and/or aliphatic diisocyanates.

In a particularly preferred embodiment of the invention, these carbodiimides/compounds correspond to formulas (II) to (IV)

and / or

Wherein R'''=C ₁ -C ₁₈ alkylene, C ₅ -C ₁₈ cycloalkyl, aryl, preferably C ₆ -C ₁₅ -exylaryl and/or C ₇ -C ₁₈ -aryl An alkyl group, and j in the molecule is the same or different and represents 1 to 5, and p may be =0 to 500, and/or a carbodiimide having a steric hindrance of formula (IV)

Wherein x = 1 to 500, preferably 1 to 50.

Due to their preparation, the abovementioned carbodiimides of the formulae (I) to (IV) can also be obtained in the form of a monomeric, oligomeric and/or polymeric mixture. These mixtures are included within the subject matter of the present invention.

These compounds of the formulae (I) to (IV) are commercially available, for example from Rhein Chemie Rheinau GmbH, or can be produced by methods well known to those skilled in the art, for example as described in DE-A-11 30 594 or In US 2 840 589, or by condensation of a diisocyanate at elevated temperatures (for example at 40 ° C to 200 ° C) in the presence of various catalysts (carbon dioxide is eliminated). Examples of catalysts which are found to be suitable include strong bases and phosphorus compounds. It is preferred to use a phospholene oxide, a phospholinidine or a phospholine oxide, and also a corresponding sulfide. Further, as the catalyst, it is possible to use a tertiary amine, an alkali metal compound, a metal salt of a carboxylic acid, and a non-basic organometallic compound.

All diisocyanates are suitable for the preparation of these compounds and/or polymers used, wherein in the context of the present invention it is preferred to use carbodia based on aromatic isocyanates substituted by C ₁ - to C ₄ -alkyl groups. Amines and/or polycarbodiimides, such as, for example, 2,4-toluene diisocyanate (TDI), 2,6-toluene diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene Mixture of isocyanates, phenyldimethyl diisocyanate, 2,6-diisopropylphenyl isocyanate, 2,4,6-triisopropylphenyl-1,3-diisocyanate, 2,4,6-triethyl Phenyl-1,3-diisocyanate, 2,4,6-trimethylphenyl-1,3-diisocyanate, 2,4'-diisocyanide diphenylmethane, 1,5-naphthalene diisocyanate , 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 1 , 3-phenylene-diisocyanate, 1,4-phenylene-diisocyanate, 2,6-diisopropylphenylene isocyanate, and 1,3,5-triisopropylbenzene 2,4-di Isocyanates or mixtures thereof. It is particularly preferred that these carbodiimides and/or polycarbodiimides are based on 2,4-toluene diisocyanate and 2,6-toluene diisocyanate or on the basis of 2,4-toluene diisocyanate and 2,6-toluene A mixture of diisocyanates.

In another embodiment of the invention, a mixture of different carbodiimides can also be used.

Particularly preferably, the solid carbodiimide used has a particle size of <50 μm.

In another preferred embodiment of the invention, the compounds of formula (I) to (IV) may exist in the form of aqueous dispersions. In these cases, the active ingredient content is preferably from 20% to 80%, more preferably from 40% to 60%.

The polyurethane dispersions for the purposes of the present invention are preferably aqueous, ionic or nonionic polyurethane or polyester polyurethanes which comprise polar groups and/or comprise Solvents, and they are based on aromatic and/or aliphatic isocyanates, preferably aliphatic isocyanates, such as, for example, hexamethylene diisocyanate. These dispersions are commercially available, for example from Bayer MaterialScience AG as "Dispercoll" U" product is obtained.

Polar groups for the purposes of the present invention are, for example, hydroxyl, sulfonate, ether or carboxyl groups.

The aqueous dispersion binder of the present invention preferably has the following composition: 0.2% to 10%, more preferably 0.5% to 5%, at least one carbodiimide having the formulae (I) to (IV) and 99.8% to 90%, More preferably, 99.5%-95% of the PU dispersion.

In both cases, the component of the active ingredient is preferably from 20% to 80%.

The carbodiimides of the formulae (I) to (IV) used are preferably solid or liquid at room temperature.

In another preferred embodiment of the invention, the solid carbodiimides of formula (I) to (IV) are surface inactivated by reaction with at least one amine.

For such surface deactivation (microencapsulation), the amines that can be used include all amine functional compounds. These are preferably polyfunctional primary and secondary amines, more preferably polyfunctional fatty amines. Suitable amines according to the invention are more particularly selected from the group consisting of cyclic and aliphatic, linear or branched (C ₂ -C ₁₄ )-alkyl amines, diamines and polyamines, more particularly ( Amines, diamines and polyamines of C ₂ -C ₁₀ )-alkyl groups, preferably amines, diamines and polyamines of (C ₂ -C ₆ )-alkyl groups, it is possible that the alkyl chain is at least partially or completely Heteroatoms (more particularly oxygen or sulfur) are interrupted, and/or include additional substituents (such as, for example, hydroxyl, carboxyl, halogen or the like).

Examples of suitable amines according to the invention include the following compounds: 2-pentamethylene-1,5-diamine and its isomers and homologs, such as, for example, 1,6-hexamethylenediamine; Butane; ethylenediamine; 1,3-propanediamine; di-ethyltriamine; tri-ethyltetramine; 3,3'-dimethyl-4,4'-diaminodicyclohexyl Methane; methyl hydrazine diamine; isophorone diamine; 4,4'-diaminodicyclohexylmethane; amines and diamines of alkanols, such as ethanolamine and diethanolamine, and/or guanamine amine. Among these amines, particularly preferred is 2-pentamethylene-1,5-diamine and its isomers and homologs such as, for example, 1,6-hexamethylenediamine.

Particularly preferably, these amines are polyfunctional primary and secondary amines, more preferably polyfunctional fatty amines, such as, for example, Jeffamine from Huntsman. T 403, diisopropanolamine from BASF AG; or guanamine amine, such as Versamid from Cognis 140, or Euretek 505 from Witco. More particularly, they are compounds having a hydrophilic group, such as in particular an amine group or a hydroxyl group, which are capable of reacting with the free isocyanate groups of the solid diisocyanate and thus forming a surface shell on the isocyanate. This shell initially inactivates these isocyanates, so examples are amines, diamines and polyamines.

In a preferred embodiment of the invention, the surface deactivating agent used is a low molecular weight mono-, di- or polyamine having one or more primary and/or secondary amine groups, the amount of which is such that Degree of activity (DD) (equivalent ratio of the amine group as a surface deactivator to the isocyanate group and/or the carbodiimide group of the carbodiimide to be deactivated (n NH ₂ /n NCO) Calculated) is between 0.2 and 8 equivalent %.

The surface deactivating agent can in particular have a molecular weight MW of up to 600 g/mol.

Herein, the concentration of the surface deactivator (amine) is preferably from 1% to 10% by weight, particularly preferably from 2% to 5% by weight, based on the amount of the adhesion promoter.

The surface deactivation process is preferably carried out by adding the amine to an aqueous dispersion of carbodiimide under agitation and/or milling, optionally further comprising a dispersant and an anti-settling agent. However, it is also possible to carry out the surface deactivation process by adding the amine to the organic dispersion of the carbodiimide in, for example, an alcohol, toluene or the like.

For this agitation/grinding operation, it is possible to use a commercial machine such as, for example, a sand mill, a dissolver or a blade agitator.

The inactivation of these diisocyanates is carried out in a manner known per se, as described in detail in EP 0 205 970 A and US Pat. No. 4,888,124, the disclosure of

a) dispersing the solid carbodiimide in powder form in an amine solution, or

b) An amine or amine solution is added to the dispersion of finely divided carbodiimide of the solid.

This surface deactivation process can occur in water and/or in organic solvents.

In still another embodiment of the invention, the aqueous dispersion binders of the invention further comprise a wetting agent and a dispersing agent, such as Tamol from BASF AG. NN 9104 or Aerosol from Cytec Surface Specialities GmbH OT45, such as Dispersogen from Clariant International Ltd. HR; and/or stabilizers, emulsifiers, thickeners, such as, for example, anti-settling agents, such as Borchi, among others Gel ALA (OMG Borchers GmbH) or Kelzan available from Monsanto S or other xanthan gum available from RTVanderbilt; and/or defoamer.

The proportion of stabilizer, emulsifier, thickener and/or antifoaming agent is preferably from 0.1% to 10%.

The invention further provides a process for the aqueous dispersion binder of the invention, wherein at least one of the formulae (I) to (IV), optionally in the form of an aqueous dispersion and/or optionally in a microencapsulation The form of the compound is incorporated into the polyurethane dispersion by agitation, which optionally includes additional additives.

In the case where the microencapsulated carbodiimide of the formulae (I) to (IV) is to be used, the aqueous dispersion binder of the present invention can also be prepared as follows:

First, one or more carbodiimides of the formulae (I) to (IV) are first incorporated into the polyurethane dispersion by stirring, optionally in the form of an aqueous dispersion and subsequently passed through the above-mentioned amines The reaction to surface inactivation.

For this combination of agitation, it is possible to use all commercial mixing elements, such as dissolvers.

An aqueous dispersion is prepared in a commercial element (such as a dissolver) using carbodiimides/compounds of formula (I) to (IV), according to methods familiar to the skilled person, optionally under additional additives. These additives are, for example, wetting agents and dispersing agents, anti-settling agents, antifoaming agents and the like.

For this preparation, the temperature is preferably in the range of from 5 to 50 °C.

The agitation of these carbodiimides is carried out using commercially available mixing elements such as, for example, a stirred tank and a dispersing machine.

The invention further provides for the use of the aqueous dispersion binders of the invention, optionally comprising additional additives, in the furniture and automotive industries, in the manufacture of footwear, and also in the textile industry, for example for the production of fabric/film composites. .

Preferred applications are the following: the operating surface and front panel of the kitchen and the dashboard in automotive engineering.

The invention further provides a novel method of making panels and/or footwear for the furniture, textiles, automotive industry by applying an aqueous dispersion binder according to the invention to such materials (eg, wood, PVC, etc.) The surface is attached to attach another layer, such as a laminate or the like.

These dispersions can be applied by spraying, painting, etc., see, for example, Ulrich Meier-Westhues, Vincentz Network, (2007), pp. 266-273.

In a preferred embodiment of the invention, the dispersions are activated by heat.

The following examples are intended to illustrate the invention without any limiting effect.

Chemicals used:

TDI carbodiimide, 2,4-toluene diisocyanate, carbodiimide of formula (II), Addolink TT, TDI isocyanate dimer available from Rhein Chemie Rheinau GmbH, Stabaxol P 200, carbodiimide based on 1,3-tetramethylbenzene diisocyanate (TMXDI), available from Rhein Chemie Rheinau GmbH, Carbodilite LA-01, based on dicyclohexylmethane 4,4'- The carbodiimide of isocyanate (H12MDI) still contains isocyanate groups, available from Nisshinbo Chemical Inc., Carbodilite HMV8 CA, carbodiimide based on dicyclohexylmethane 4,4'-diisocyanate (H12MDI), Nisshinbo Chemical Inc. available, Tween 85, wetting/dispersing agent, from M Nzing Chemie GmbH, Kelzan S, anti-settling agent, available from Monsanto, Jeffamin T 403, a polyetheramine for surface deactivation, available from Huntsman International LLC, Agitan 281, defoamer, available from Fluka, Dispercoll U53, 40% of an anionic high molecular weight polyurethane dispersion Dispersion, available from BayerMaterialScience AG, and Borchi Gel L 75, anti-settling agent, available from OMG Borchers GmbH.

Table 1 summarizes the preparation of aqueous Addolink Dosage in TT or TDI carbodiimide dispersion:

In Examples 1, 2, 4 and 5, water and a wetting/dispersing agent as well as an antifoaming agent (Agitan 281 and Tween 85) were combined and dissolved/mixed. The crosslinker is then added and the mixture is homogenized in a dissolver. Subsequently, in addition to in Example 5, add Jeffamin T 403 is mixed in to avoid shearing force. Thereafter, the newly prepared Kelzan The S formulation is mixed and homogenized. In Example 3, the crosslinker was dissolved in water.

Example 6: The invention

2.5 parts of the dispersion from Example 1 and one (1) part of Borchi Gel in 96.5 Dispercoll U53 L 75 is stirred together.

Example 7: Comparative

2.5 parts of the dispersion from Example 2 and one (1) part of Borchi Gel in 96.5 Dispercoll U53 L 75 is stirred together.

Example 8: Comparative

2.5 parts of the dispersion from Example 3 and one (1) part of Borchi Gel in 96.5 Dispercoll U53 L 75 is stirred together.

Example 9: Comparative

2.5 parts of the dispersion from Example 4 and one (1) part of Borchi Gel in 96.5 Dispercoll U53 L 75 is stirred together.

Example 10: Comparative

2.5 parts of the dispersion from Example 5 and one (1) part of Borchi Gel in 96.5 Dispercoll U53 L 75 is stirred together.

Example 11: Comparative

Dispercoll U53 with a quantity of 99.0 parts and one (1) part of Borchi Gel L 75 is stirred together.

These dispersions were used for the heat deformation tolerance test. For this purpose, a piece of wood was bonded to a PVC sheet, wherein 0.15 g of the dispersion adhesive from Examples 6, 7, 8, 9, 10 or 11 was applied to the wood side over a 20 x 20 mm bond area and 0.08 g of the dispersion binder from Examples 6, 7, 8, 9, 10 or 11 was applied sideways to the PVC. The sheets were then pressed at 80 ° C for 5 minutes with a 5 kg weight.

In the dry box, each weight structure weighing 5 kg was suspended in the test sample produced above. Starting at a temperature of 40 ° C, heating was carried out at a rate of 10 K/h.

The temperature at which the bond failed and the weight dropped was measured. These results are shown in Table 3 below:

The results of this experiment clearly show that the aqueous dispersion binder of the present invention exhibits greater thermal deformation stability for a given amount.

Claims (8)

An aqueous dispersible binder comprising at least one polyurethane dispersion and at least one carbodiimide having the following formula (II), (III) and/or (IV) Wherein R'''=C ₁ -C ₁₈ alkylene, C ₅ -C ₁₈ cycloalkyl, aryl and/or C ₇ -C ₁₈ arylalkyl, and the j in the molecule is the same Or different and represents 1 to 5, and p can be 0 to 500, Where x=1 to 500. According to the aqueous dispersion adhesive of claim 1 of the patent application, It is characterized in that the carbodiimide is surface deactivated by reaction with at least one amine. The aqueous dispersion binder according to the first aspect of the invention is characterized in that the carbodiimide is present in the form of an aqueous dispersion. The aqueous dispersion binder according to item 1 of the patent application, characterized in that the polyurethane dispersion is substantially an aqueous dispersion. The aqueous dispersion adhesive according to claim 1 of the invention, characterized in that the polyurethane dispersion comprises an aqueous polyurethane, an ionic polyurethane or a nonionic polyamine Carbamates, and polyester polyurethanes, which contain polar groups and/or contain solvents, are based on aromatic and/or aliphatic isocyanates. The aqueous dispersion adhesive according to Item 1 of the patent application further includes a stabilizer, an emulsifier, a thickener, and/or an antifoaming agent. A method for preparing an aqueous dispersion binder according to claim 1 of the invention, characterized in that at least one carbodiimide of the formula (II) to (IV) is bonded to the polyamino group by stirring In the ester dispersion. A method for producing panels and/or footwear for the furniture, textile and automotive industries, comprising applying the aqueous dispersion adhesive according to claim 1 of the patent application to panels and/or footwear of the furniture, textiles and automotive industries on the surface.